Method and apparatus for reorienting blanks while feeding individual blanks from a stack to an erecting machine

ABSTRACT

A method and apparatus is disclosed for conveying individual blanks, one at a time, from a stack of blanks in a magazine to a form chamber in an erecting machine. The magazine includes bottom and side guides and a conveyor for moving the blanks into a pickup position. A suction cup device is utilized to grip an upper portion of the blank in the pickup position and swing the blank into engagement with a bolster roller set. A segment device having a curved surface is also disclosed for coacting with the bolster roller for swinging the blank from a substantially vertical position to a substantially horizontal position for conveying into an erecting machine.

The present invention relates to a method and an arrangement forconveying blanks in an erecting machine from a stack of blanks, whichare intended to be picked one at a time from the stack and conveyedfurther to a form chamber in an erecting machine, where the blank isformed into a container with the aid of a plunger. The magazine includesbottom and side guides, as well as means for conveying the blanks,upstanding on edge, forward to the exit or delivery end of the magazine.There are also means for conveying the blanks, after they exit from themachine, to the form chamber, where they are formed into containers withthe aid of the plunger.

In the types of erecting machines at present on the market, there areconsiderable problems with the mechanisms transferring the blanks fromthe magazine and advancing them into the erecting machine itself, i.e.there are stoppages in the flow of blanks, or two or three blanks areadvanced simultaneously, thus causing machine downtime. Another problemis that most erecting machines have magazines, where the blanks arestacked one on top of the other, resulting in that filling the magazineis both difficult and laborious.

The object of the present invention is to eliminate the drawbacksburdening previously known apparatus of the kind mentioned above, and toachieve a method and an arrangement in erecting machines for conveyingblanks from a magazine such as to take place without unnecessarydowntime, as well as at very high machine speeds, while the arrangementfor carrying out the method has apparatus having a construction which issimple and reliable. The features distinguishing the invention aredisclosed in the accompanying claims.

By reason of the present invention there has now been provided a methodand an arrangement of the kind mentioned above, for conveying blanksthat are stacked on edge in a magazine. With the blank picking apparatusincluded in the inventive arrangement the magazine may now be placed atworking height, signifying several advantages from the ergonomic aspect,particularly for the personnel who daily attend the machine. The pickingapparatus includes at least one suction cup device, the cup of whichattaches itself to the blank nearest to it in the magazine, the devicedrawing the blank from the magazine such as to give the blank a curvedconfiguration, while taking the upper portion of the blank intoengagement against a bolster roller. Also part of the picking apparatusis a swinging segment device, which moves such as to press a portion ofthe blank against the bolster roller while moving at a peripheral speed,which is the same as that of the roller, the device and roller thusurging the blank to an advancing means, e.g. a set of rollers. By thisarrangement the blank is re-oriented from an upstanding attitude in themagazine to a horizontal attitude for advancing to the form chamber inthe erecting machine. With this horizontal orientation the blank isurged downwards in the form chamber using a plunger, thus forming thepackaging container. Only one blank at a time is picked by the inventiveblank picking apparatus, since the intrinsic resistance to bending ofthe blanks causes the blank next to the one being withdrawn to separatefrom it as the suction cup device draws the blank it is attached to intoa curved configuration, the problem caused by two or more blanks beingpicked simultaneously thus being eliminated. Due to the simplicity ofthe apparatus, where few moving parts are required for the actualpicking and translation of the blanks from vertical to horizontalorientation, very high machine speeds can be maintained, and of courselarge capacity as a result.

The invention will now be described in more detail below, using apreferred embodiment example, and with reference to the accompanyingdrawings, where:

FIG. 1 is a perspective view of one end of an erecting machine operatingwith two magazines, of which the one to the right is shown loaded withblanks on edge, the inventive blank picking apparatus being placed atthe blank exit end of the magazine.

FIG. 2 is a schematic side view of the inventive arrangement foradvancing the blanks, and from which may be understood the blank pickingprinciple.

FIG. 3 is an oblique view from above, showing part of the arrangement inFIG. 1 for picking and advancing the blanks.

FIG. 4 is a perspective view of the other end of the machine in FIG. 1,a blank being in a position partially covering the form chamber, andwith the plunger above it.

FIG. 5 is a schematic side view of another embodiment, from which may beunderstood in principle the picking and apparatus for the blanks.

FIG. 6 is an enlarged side view of a segment device, seen from the otherside of the one illustrated in FIG. 1, and intended for coaction with abolster roller.

As will be seen from the drawings, the object of the arrangement,according to a preferred embodiment, is to convey packaging blanks 3,stacked on edge in at least one magazine 2 at working height, to a formchamber 4 in an erecting machine 1, the blanks being in a horizontalposition above the chamber for erection by a plunger 5. Immediately infront of the magazine exit 6, and at its upper portion 7, there isapparatus which includes a device 8 including a vacuum-operated suctioncup. The device is pivotably mounted such as to enable it to urge theblank upper portion 9 against at least one bolster roller 10, which issituated between the magazine 2 and at least one advancing roller set 11situated above, and in association with, a conveyor 12.

The magazine 2 itself is somewhat downwardly sloping in a directiontowards its exit 6, and is disposed at working height on the erectingmachine 1. Packaging container blanks 3 are placed on edge, one againstthe other, in the magazine and are laterally positioned with the aid ofguides 13, while resting on a bottom guide 14, which in this caseincludes means 15 for advancing the blanks 3 forwards to the magazineexit 6 or discharge end. The suction cup device 8 is pivotably mountedon a shaft 16, about which it swings between two positions for providingthe outward flexing of one blank 3 at a time. When the device 8 is in aposition for extracting a blank its suction cup 17 is put under vacuumfor attracting the outmost blank, giving it an outward curvature as thesuction cup 17 moves to its outwardly swung position, with the blankurged against the bolster roller 10. Vacuum is released at this stage,and the suction cup releases the blank, which can then be advanced overthe roller 10 with the aid of at least one segment device 18 pressingagainst the blank from above. In the embodiment example illustrated inFIGS. 1-4, there are two such devices 18 for each blank, and they areadapted to swing with the aid of a shaft 19, which extends above thebolster rollers 10.

The blank 3 is thus advanced from its substantially vertical state, andis passed over the rollers 10 with the aid of segment devices 18 in anarcuate movement, and into horizontal orientation as it coacts with theroller set 11. In certain cases, when the blank is coacting with theroller set 11, the advancing speed may be increased, which enablesgreater flexibility in the sizes of blank format that can be used. Asegment device 18 is illustrated to an enlarged scale and in more detailin FIG. 6. To ensure that the blank is not torn apart when it isadvanced with the aid of the roller set 11 at a greater speed, thesegment devices 18 are each provided at its rear edge 22 with a springbiassed trailing portion 20, which can move in an upward direction torelease or reduce its pressure against the blank 3 when the roller setcoacts in advancing the blank at a speed which can be greater than it isover the bolster rollers 10. The portion 20 at the rear or trailing edge22 is pivotable about a pin 23, and is kept in its normal position withits curved surface 24' in line with the curved surface 24 of the segmentdevice 18 with the aid of spring bias, e.g. from a compression spring25. For obtaining less pressure against the blank, the portion 20 willmove into the position shown by dashed lines in FIG. 6. The result ofthis mechanism is the avoidance of excessive tensile stress in a blankas it starts to coact with the roller set 11 for advancement, which canbe at a greater speed than the blank had before.

In the embodiment example of the inventive arrangement for conveyingpackaging blanks from a stack of them in the magazine 2 to the erectingchamber, as illustrated in FIG. 5, the suction cup device 8 is alsomovable in a substantially vertical direction, from a lower blankpicking position to an upper blank releasing position. In the former,where the upper portion 9 of the blank 3 engages the bolster rollers 10,vacuum is released simultaneously as the segment device 18 has swunginto position for urging the blank against the bolster rollers 10, fortaking the blank further to the roller set 11, from whence the blank isfurther advanced in a horizontal attitude and via the conveyor 12 up tothe form chamber 4 of the erecting machine 1.

In order to increase friction over the bolster rollers 10, as well as onthe segment devices 18, their respective curved surfaces may be providedwith friction-increasing material, e.g. rubber. The conveyor 12 incoaction with the roller set 11 takes the blanks to the form chamber 4in the machine 1. In the present case, the conveyor includes a pluralityof hollow bands 21 having holes communicating with vacuum, forincreasing friction with the conveyed blanks. When the blanks 3 havecome to the form chamber 4 in the machine 1 they are conventionallyerected with the aid of the plunger 5, such as to form a packagingcontainer, which is then ejected onto a delivery conveyor disposed underthe form chamber 4, this conveyor also being at working height.

The method of conveying the blanks from the magazine 2 to the formchamber 4 in the machine 1 is carried out as follows. One blank 3 at atime is taken from the exit end 6 of the magazine 2 with the aid of thesuction device. 8, the suction cup 17 of which attaches itself by vacuumto the upper portion 9 of the blank such as to flex it outwards, forsubsequently bringing, as illustrated by the example in FIG. 5, theupper portion of the blank 3 into engagement with the bolster rollers 10situated in front of the advancing roller set 11. The amount of outwardswing of the blank upper portion 9 may be between 10° and 45° from avertical plane, and is preferably 15° . When the blank 3 engages thebolster rollers 10, the segment devices 18 are given their swingingmovement, which presses the blank 3 against the rollers simultaneouslyas the swinging movement is synchronous with the roller rotation. Theblank 3 is thus advanced between roller and segment simultaneously as itis flexed over the rollers 10, according to the embodiment exampleillustrated in FIGS. 1-4, and thus assumes a substantially horizontalposition for advancing to the following roller set 11. In the otherembodiment example illustrated in FIG. 5, flexing the blank 3 to itshorizontal attitude preferably occurs within the extension of the rollerset 11. In order to obtain as great a flexibility in format size aspossible, the advancing speed of the set 11 may be greater than thatover the rollers 10. With this in mind, the segment device 18 may beprovided with the upwardly spring biassed trailing portion 20. When theblank 3 comes into coaction with the roller set 11, the spring biassedportion 20 of the segment device 18, see FIG. 6, is in engagement withthe blank 3 and is pressing it against the rollers 10, simultaneously asthe pressure, by reason of the resilient property of the trailingportion 20, enables the blank to be drawn into coaction with the rollerset 11 at a greater speed than the blank had over the bolster rollers10. In other words, the nip between the bolster rollers 10 and thesegment devices 18 is implemented such that the blank 3 may be drawnthrough it due to reduction in friction. After passing the roller set 11the blanks 3 are further advanced by the conveyor 12 up to the formchamber 4 in the erecting machine 1, and in the embodiment example inquestion this conveyor 12 is provided with the mentioned hollow bands21. These have holes that can be put under vacuum, so that frictionbetween said bands 21 and the blanks 3 conveyed on them will be as greatas possible. Other conveying means may also be used, of course. Theblank 3 is then positionally fixed above the form chamber 4, after whichthe plunger 5 erects the blank 3 while urging it downwards onto aconveyor (unillustrated on the drawing) situated under the form chamber4, this conveyor then discharging the erected blanks in the form ofpackaging containers from the erecting machine 1.

I claim:
 1. Method of conveying packaging blanks from a stack of blanks(3) placed in at least one magazine (2), said magazine being providedwith an exit end having an upper portion, said blanks including aforemost blank and being picked one at a time from the magazine (2) andconveyed further to a form chamber (4) in an erecting machine (1), wheresaid blanks are formed into packaging containers with the aid of aplunger (5), whereby the foremost blank (3) of said stack of blanks (3)on edge and one against the other in the magazine (2) is gripped at itsupper portion (9) with the aid of vacuum by at least one suction cupdevice (8), and after being swung outwards is brought into engagementwith a bolster roller (10) having a rotational speed, which is situatedin association with said upper portion (7) of the exit end of themagazine (2) and immediately in front of an advancing roller set (11)having an advancing speed, the blank (3) in this position being pressedagainst the bolster roller (10) by at least one segment device (18),which is caused to swing down onto the blank (3) to cause said blank toswing outward, said segment device swinging with the same rotationalspeed as the bolster roller (10) with the blank pressed between them,characterized in that, during the outward swing of the upper portion (9)of the blank (3), the suction cup device (8) brings it into directcontact against said bolster roller (10), situated immediately in frontof the magazine (2) and mainly in a level with and in direct associationwith the advancing roller set (11) and in which position the segmentdevice (18) from above presses the blank (3) against the bolster roller(10), such that the blank (3) is advanced forward and flexed over thebolster roller (10) from the substantially vertical attitude of saidblank in the magazine (2) to a substantially horizontal attitude duringthe advance into the roller set (11) in further advancing the blank (3)to the form chamber (4) in the erecting machine (1); said segment device(18) having a rear portion (20), which resiliently presses against theblank (3) such as to permit an increase in the speed of the blank (3)when it is advanced by the advancing roller set (11), simultaneously assaid portion (20) moves resiliently to release the blank (3).
 2. Methodas claimed in claim 1, characterized in that the advancing speed isgreater within the roller set (11) than over the bolster roller (10) forachieving greater flexibility in format size.
 3. Method as claimed inclaim 1, characterized in that after the roller set (11) the blanks (3)are conveyed to the form chamber (4) by a conveyor (12) provided withhollow bands (21), which are provided with holes in communication withvacuum for increasing friction between the blanks (3) and said conveyingmeans (21).
 4. Arrangement as claimed in claim 1, characterized in thata conveyor (12) is provided in association with the roller set (11) forconveying the blanks (3) forward to the form chamber (4) in the erectingmachine (1), said conveyor (12) including conveying means comprisinghollow bands (21) having holes, which are in communication with vacuumfor increasing friction against the blanks (3) carried by them. 5.Arrangement in an erecting machine, including apparatus for pickingpackaging blanks from at least one magazine, said blanks having an upperportion, said apparatus being (2) provided with bottom and side guides(13, 14) as well as means (15) for advancing the blanks (3) upstandingand on edge in the magazine to its exit end (6), and advancing apparatus(10, 11, 12) for further conveyance of the blanks, after their removalfrom the magazine, to a form chamber (4) in the erecting machine (1),where the blanks are formed into packaging containers with the aid of aplunger (5), whereby after, and in association with, the exit end (6) ofthe magazine (2) there is at least one suction cup device (8) operatingby vacuum, the device being adapted to swing out the upper portion (9)of the blank (3) and bring it into engagement against at least onebolster roller (10) situated in association with at least one advancingroller set (11) provided in the advancing apparatus (10-12) and at leastone device (18) coacting with said bolster roller (10) such as toadvance between them the blank (3), characterized in that said bolsterroller (10) is situated immediately in front of the magazine (2) andmainly in a level therewith and in direct association with the advancingroller set (11) and in that said device (18), device coacting with saidbolster roller (10) consists of a segment device having a curvedsurface, said device situated with its swing axis mainly straight abovesaid bolster roller (10) to use a swing movement to feed the blank (3)from a substantially vertical attitude in the magazine (2) and flex itaround said bolster roller (10) to a substantially horizontal feeddirection to further advance to the form chamber (4) in the erectingmachine (1), said segment device (18) having a rear portion (20), whichis spring biassed in an upward direction for releasing or decreasing thepressure against the blank (3) when the latter is in coaction with theadvancing roller set (11).
 6. Arrangement as claimed in claim 5,characterized in that the bolster roller (10) has its curved surfacedisposed for high friction, and is preferably rubber covered, as withthe curved surface of the segment device (18).